Not sure if this is And You Thought It Was a Game

I saw a BBC movie on PBS called An Englishman's Castle, about a Nazi-occupied Britian. TV Tropes only mentions it once, under Alternate History.

I am going to spoil the ending. The hero's girlfriend is supposed to sing a famous song, "Britons strike home", and that is to signal a massive uprising against the Nazis. But she'd be quickly killed, and the hero wants to save her. So he's in a position to interrupt the broadcast and he directly tells the viewers, "Britons, strike home. Repeating, Britons, strike home." Then he loads his gun, faces the door of his office and the movie ends there. This movie, and the song, both have Wikipedia entries.

Well, I couldn't decide which trope that would be. It's not quite, "All Part of the Show." How about, "You just Ruined the Shot"? Not quite that, either. "And You Thought It Was A Game"?

It is not any of those.

• All Part of the Show can only happen if the stuff is really not part of the show. The hero intended all along that his command, "Britons, strike home," is part of the show.
• You Just Ruined the Shot requires one to mistake the show for reality. And You Thought It Was a Game requires one to mistake reality for a show. The hero intentionally broadcasted a command, so he has no confusion about whether it is a show.

Lost And Found might help with finding a correct trope.